Dr Mike O'Sullivan
My main research interest is the overlap and interaction of Alzheimer’s disease and cerebrovascular disease at the level of distributed cognitive networks within the brain.
My current research combines structural and functional MRI based at the new CUBRIC centre to explore the role of fronto-temporal tracts in memory and in the memory deficits of ‘mild cognitive impairment’ (mediated by both incipient Alzheimer’s disease and vascular mechanisms). A particular focus is the translation of insights from non-human primate models of frontotemporal disconnection and from advances in theoretical and anatomical models of memory.This work builds upon previous investigations applying diffusion tensor MRI to explore the mechanisms of executive dysfunction in common sporadic and genetic forms of cerebral small vessel disease, and more recently, studies of the impact of pure vascular disease on the hippocampus through the application of CADASIL as a genetic model.
Other research interests include alterations in cerebral blood flow in small vessel disease investigated with perfusion MRI. We previously found evidence that hypoperfusion plays a causal role in white matter damage in small vessel disease. We are planning to extend this work to studies of blood flow in the hippocampus and related network in mild cognitive impairment, adopting non-invasive continuous arterial spin labelling MRI, again to probe the links between vascular and degenerative mechanisms.
Selected Publications
O’Sullivan M, Ngo E, Viswanathan A, Jouvent E, Gschwendtner A, P Saemann, Duering M, Pachai C, Bousser M-G, Chabriat H, Dichgans M. Hippocampal volume is an independent predictor of cognitive performance in CADASIL. Neurobiology of Aging 2007 (in press) [link]
Jouvent E, Mangin J-F, Porcher R, Viswanathan A, O’Sullivan M, Guichard J-P, Dichgans M, Bousser M-G, Chabriat H. Cortical changes in cerebral small vessel diseases: a 3D MRI study of cortical morphology in CADASIL. Brain 2008; 131: 2201-2208. [link]
O’Sullivan M, Barrick TR, Morris RG, Clark CA, Markus HS. Damage within a network of white matter regions underlies executive dysfunction in CADASIL Neurology 2005; 65:1584-90. [pdf]
O’Sullivan M, Jones DK, Summers PE, Morris RG, Williams SCR, Markus HS. Evidence for cortical ‘disconnection’ as a mechanism of age-related cognitive decline. Neurology 2001;57:632-638. [pdf]
Research Projects
MRC Clinician Scientist Fellowship (2008-2012, £1M) “Fronto-temporal connectivity and memory: patterns of breakdown in ageing and diseases of old age.”
Alzheimer’s Research Trust. 2010-2011, £30 000. “Cerebral small vessel disease, blunted perfusion responses and adaptation to early Alzheimer’s disease.” £30 000 (with Prof DK Jones, Prof RG Wise, Dr T Bayer and Dr K Murphy)
Research Students
Julie Dumont (jointly with Prof John Aggleton)
Related Links
Memory Interest Group